Question

What is the line of symmetry for the graph of y = -3x^2 + 12x - 11?

1.) x=-4
2.) x=-2
3.) x=2

Answer 1

Isn't that where the vertex is at?

Answer 2

Solving it calculus wise..
\[\large -3x^2+12x-11\]
\[\large y'=-6x+12\]
\[\large 0=-6x+12\]
\[\large x=2\]

Answer 3

It's algebra

Answer 4

Vertex formula \(\large \frac{-b}{2a}\)

Answer 5

So.. \[\LARGE \frac{-12}{2(-3)}=\frac{-12}{-6}=?\]

Answer 6

2

Answer 7

So x=2 ..?

Answer 8

Yup~